What EPA's radon map says about Falls Church city

EPA's own radon map rates Falls Church city zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Nationally, Falls Church city ranks higher in radon potential than 79% of rated counties (the 79th percentile).

Falls Church city by the numbers

About 15,034 people live in Falls Church city, Virginia, spread over 2.046 square miles. That works out to roughly 7,348 people per square mile. Among counties sharing Falls Church city's EPA zone, it outranks 38% of them by population.

Zone vs. an actual test

Where the national indoor average runs about 1.3 pCi/L, Falls Church city's Zone 1 rating puts its predicted county average above EPA's 4 pCi/L action level itself. A Zone 1 rating means testing is worth doing sooner rather than later, but it is still county-wide average, not a reading for any single house — some homes in Falls Church city will test well under the action level, and EPA's guidance is to test regardless of zone.

Next steps for a home in Falls Church city

Mitigation cost doesn't depend on Falls Church city's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find Virginia's state radon program

Falls Church city's test kit answers today; a Airthings radon monitor keeps answering for Falls Church city over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. Use code RADONZONE-10OFF at checkout for 10% off.

More on how this number was built

The methodology guide shows exactly which EPA and Census sources feed Falls Church city's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.